mark i have two racks i use. the easy one is a front hitch on my truck (bolt on and hidden behind the front bumper) with a standard thule 4 bike carrier. the other one is a simple design. i welded two receiver tubes, one on each frame rail. then i constructed a square tube frame with expanded metal(mesh) for the floor. its not that heavy, its very safe and sound. its removable if needed and it does'nt rock at all. it will void your frame warrenty, but that didnt bother me because the chassis builder is a lousy company called lippert. i built originally for my schwinn tandem bike, but now i carry my fire pit, generator and anything else i might need. do a search i posted pictures awile ago. if you cant find them i'll try to repost them. i would'nt even carry my spare tire on the bumper, much less 4 bikes. good luck
p.s. if you dont/cant weld this is something any average welder can make. its not that complicated. good luck.
just copy and paste the link if it does'nt work for you.
edit: heres the post with pictures. http://www.crossroadsrv.com/forum/forum_posts.asp?TID=1990&KW=bike+rack&PID= 18792#18792Edited by: spinella